This Application claim priority under 35 U.S.C. xc2xa7119 of Italian application number TO2001A 000445, filed May 11, 2001 in Italy.
The present invention relates to a vane for a stator of a variable-geometry turbine, in particular of an axial turbine for aeronautical engines.
As is known, an axial turbine for an aeronautical engine comprises at least one stator and one rotor arranged in succession to each other and comprising respective arrays of vanes delimiting between them associated nozzles through which a flow of gas can pass.
In aeronautical engines, it has been found necessary to use axial turbines having relatively high efficiency in all operating conditions and, therefore, over a relatively wide range of values for the rate of flow of the gases that pass through the turbine itself.
This requirement could be met by producing variable-geometry turbines, i.e. turbines in which it is possible to vary the transverse area of the nozzles of at least one stator, in particular by adjusting the angular position of the stator vanes about respective axes incident to the axis of the turbine.
In use, however, the operating temperatures of the turbine are extremely high and involve considerable thermal expansion of the vanes and other components, so that jamming or outright seizure could occur between the movable vanes and the fixed parts of the stator, consequently compromising the functionality of the turbine.
The purpose of this invention is to produce a vane for a stator of a variable-geometry turbine, in particular for aeronautical engines, which allows the problems set out above to be solved simply and economically.
According to the present invention, a vane is produced for a stator of a variable-geometry turbine, in particular for aeronautical engines; the vane comprising an airfoil profile and means for coupling said airfoil profile to a support structure of said stator; characterised in that said coupling means comprise hinge means carried by said airfoil profile to allow rotation of the airfoil profile itself with respect to said support structure about an axis of adjustment, and in that it comprises means for cooling said hinge means.
The present invention also concerns a stator of a variable-geometry turbine, in particular for aeronautical engines.
According to the present invention, a stator of a variable-geometry turbine is produced, in particular for aeronautical engines; the stator comprising a support structure and a plurality of vane members delimiting between them a plurality of passages for a flow of gas; each vane comprising an airfoil profile and means for coupling said airfoil profile to said support structure; characterised in that said coupling means comprise hinge means carried by said airfoil profile to allow the rotation of the airfoil profile with respect to said support structure about an axis of adjustment, and in that it comprises means for cooling said hinge means.